Fix audio tooltip logic (#21941)

Earlier work by @osiewicz in #21931 aims to fix audio control tooltips
in the title bar to close #21929. However, its logic is not quite
correct, and does not match the toggle behavior for the controls.

This PR corrects the logic to match the toggle behavior for the
controls. It also updates capitalization and wording for consistency.

Release Notes:

- N/A

crates/call/src/cross_platform/room.rs

@@ -1288,6 +1288,12 @@ impl Room {
         })
     }
 
+    pub fn muted_by_user(&self) -> bool {
+        self.live_kit
+            .as_ref()
+            .map_or(false, |live_kit| live_kit.muted_by_user)
+    }
+
     pub fn is_speaking(&self) -> bool {
         self.live_kit
             .as_ref()

crates/call/src/macos/room.rs

@@ -1307,6 +1307,12 @@ impl Room {
         })
     }
 
+    pub fn muted_by_user(&self) -> bool {
+        self.live_kit
+            .as_ref()
+            .map_or(false, |live_kit| live_kit.muted_by_user)
+    }
+
     pub fn is_speaking(&self) -> bool {
         self.live_kit
             .as_ref()